1. Field
The exemplary embodiments generally relate to exercise machines and, more particularly, to weight bearing exercise machines providing lower body exercise.
2. Brief Description of Related Developments
Several types of weight-bearing exercise machines provide lower body exercise for muscle strengthening, cardiovascular conditioning, sport training and rehabilitation. This category of machines includes ski trainers, striders, steppers, elliptical trainers and exercise bikes. Most of these devices restrict motion to the midline (forward and backward, up and down), thereby focusing on the flexor and extensor muscles of the hip and leg. As a result, they largely neglect the hip adductor and abductor muscles (and other lateral stabilizers) that help coordinate lateral balance and changes of direction, which are integral to daily activities and athletics (especially skating, downhill skiing, field sports, court sports, and dance).
Some previous weight bearing exercise machines provide lateral leg exercises that engage the lateral stabilizers along with the other muscles of the legs and torso. Conventional designs for lateral leg motion vary according to whether the left and right feet move dependently (fixed stance) or independently (variable stance) and, less importantly, whether the foot platforms are supported and guided from below (by sliding or rolling on a flat or curved track), from the side (by rotating radially on a horizontal arm), or from above (by swinging on pendulum-like stems suspended side-by-side from an upright frame).
However, conventional lateral exercise machines have important limitations including a lack of full independent lateral leg motion (apart-and-together or side-to-side). Thus their restricted motions often fail to isolate or fully engage the hip adductors. Furthermore, these devices lack a mechanism for opposing resistances to abduction and adduction that are separately, incrementally and conveniently adjustable by the user. In addition, conventional weight-bearing exercise machines generally do not combine full independent lateral leg motion with a full fore-aft striding motion, or combine independent lateral, fore-aft and vertical leg motion on a single machine, which would activate a wider variety of leg muscles in combination or in sequence.
Examples of conventional weight-bearing exercise machines include various downhill ski trainers (e.g. U.S. Pat. Nos. 4,650,184; 3,511,499; 5,232,423; 7,090,621; 6,231,484; 6,117,052; 5,429,567, and Skier's Edge®), skating machines (e.g. U.S. Pat. Nos. 5,496,239; 5,284,460; 7,115,073), fore-aft striders (e.g. U.S. Pat. Nos. 4,850,585; 5,419,747; 5,496,235; 5,792,027), other lateral trainers (e.g. U.S. Pat. Nos. 5,536,255, 4,861,023, 6,042,510 and Leg Magic™), elliptical trainers (e.g. U.S. Pat. Nos. 6,786,851, 7,025,710), and other devices with limited multidirectional motion (e.g. U.S. Pat. Nos. 6,508,746, 5,429,567 and the Shuttle Balance™ system).
It would be advantageous to have a single exercise machine that provides multi-axial independent leg motion including lateral abduction and adduction (apart-and-together or side-to-side), forward and backward striding, and/or vertical flexion and extension against variable resistances that are separately and conveniently adjustable during or before use.